Question

The atomic number of Calcium is _______.

Answer 1

Calcium:

1. The chemical element calcium has the atomic number 20 and the letter $\mathrm{Ca}$ as its symbol.
2. Calcium is an alkaline earth metal that reacts with air to create a black oxide-nitride coating.
3. Its heavier homologs Barium and Strontium are most comparable to it in terms of physical and chemical characteristics.
4. The electronic configuration of Calcium is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^2$.